Oswaldo César de Almeida Filho

Forma Indeterminada da Moléstia de Chagas: Proposta de Novos Critérios de Caracterização e Perspectivas de Tratamento Precoce da Cardiomiopatia

Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto – USPCorrespondencia: Jose Antonio Marin-Neto – Divisao de Cardiologia, Depto. deClinica Medica - Hospital das Clinicas, FMRP-USP – Av. Bandeirantes, 390014048-900 - Ribeirao Preto, SP - E-mail: marin_neto@yahoo.comRecebido para publicacao em 26/2/02Aceito em 27/5/02

Right Ventricular Doppler Echocardiographic Study of Indeterminate Form of Chagas Disease

Background Patients with indeterminate form of Chagas disease/cardiac normality (ICD/CN) exhibited normal electrocardiograms and chest X-rays; however, more sophisticated tests detected some degree of morphological and functional changes in the heart. Objective To assess the prevalence of systolic and diastolic dysfunction of the right ventricle (RV) in patients with ICD/CN. Methods This was a case–control and prevalence study. Using Doppler two-dimensional echocardiography (2D), 92 patients were assessed and divided into two groups: group I (normal, n = 31) and group II (ICD/CN, n = 61). Results The prevalence of RV systolic dysfunction in patients in groups I and II was as follows: fractional area change (0.0% versus 0.6%), mobility of the tricuspid annulus (0.0% versus 0.0%), and S-wave tissue Doppler (6.4% versus 26.0%, p = 0.016). The prevalence of global disorders such as the right myocardial performance index using tissue Doppler (16.1% versus 27.8%, p = 0.099) and pulsed Doppler (61.3% versus 68%, p = 0.141) and diastolic disorders such as abnormal relaxation (0.0% versus 6.0%), pseudonormal pattern (0.0% versus 0.0%), and restrictive pattern (0.0% versus 0.0%) was not statistically different between groups. Conclusion The prevalence of RV systolic dysfunction was estimated to be 26% (S wave velocity compared with other variables), suggesting incipient changes in RV systolic function in the ICD/CN group.

A Challenging Differential Diagnosis: Distinguishing between Endomyocardial Fibrosis and Apical Hypertrophic Cardiomyopathy

Endomyocardial fibrosis, which is a cause of restrictive cardiomyopathy, is characterized by the deposition of fibrous tissue in the apical region of 1 or both ventricles. The condition not only affects the diastolic dynamics of the ventricles, but also the function of the atrioventricular valves. The disease occurs predominantly in tropical regions worldwide and in sub‐Saharan Africa. This condition is not well understood, with varied manifestations, from subclinical presentations to chronic and progressive edematous syndromes. Here, we present the challenging case of a patient with an indeterminate echocardiographic image, suggesting apical hypertrophy, plus severe aortic stenosis and fibrosis of the left ventricular outflow tract. An electrocardiogram revealed symmetrical T‐wave inversion, which is a characteristic manifestation of apical hypertrophy. The importance of cardiac imaging examinations such as echocardiography and cardiac magnetic resonance for differentiating between endomyocardial fibrosis and apical hypertrophy is highlighted in this patients case.

Is Left Ventricular Diastolic Thickening Documented During Dobutamine and Pacing Stress Echocardiography Related to Myocardial Ischemia? An Animal Model Study

Transient increase in diastolic wall thickness (pseudohypertrophy) during pacing stress echocardiography has been reported in normal myocardium. To evaluate the occurrence of pseudohypertrophy and to investigate the contribution of myocardial ischemia on its production during pacing and dobutamine stress echocardiography, we produced a physiologically significant coronary stenosis in 14 open chest dogs. The stenosis in the circumflex artery was measured by quantitative coronary angiography (range: 50% to 89% reduction in luminal diameter), and no resting segmental wallmotion abnormalities were observed by epicardial echocardiography (short‐axis, papillary level). In each study, dobutamine (5–40 μg/kg/min) and pacing (up to 260 beats/min) were performed randomly. Positivity of stress echocardiography tests was quantitatively determined by a significant (P < 0.05) reduction or failure to increase in absolute and percent systolic wall thickening in the myocardial area supplied by the stenotic artery as compared to the left anterior descending (LAD) artery‐related areas. Diastolic wall thickness and left ventricular diastolic area were compared before and after each stress test in the circumflex and LAD artery‐related regions. Pseudohypertrophy was observed in 57% and 86% of dogs for pacing and dobutamine, respectively, in the circumflex region, and in 50% and 64% in the LAD region. Despite its increased incidence in the circumflex region, the augmented diastolic wall thickness did not correlate with coronary stenosis severity or stress test positivity, but correlated inversely with changes in left ventricular diastolic area. In addition, it correlated directly with changes in heart rate only for pacing. In conclusion, pseudohypertrophy was a frequent finding during pacing and dobutamine stress echocardiography tests but was not related to myocardial ischemia in this animal model.